Monolithic Multiparameter Terahertz Nano/Microdetector Based on Plasmon Polariton Atomic Cavity

Terahertz (THz) signals are crucial for ultrawideband communication and high-resolution radar, demanding miniaturized detectors that can simultaneously measure multiple parameters such as intensity, frequency, polarization, and phase. Traditional detectors fail to meet these needs. To address this, we introduce a plasmon polariton atomic cavity (PPAC) detector based on monolayer graphene, offering a multifunctional, monolithic, and miniaturized solution. With a footprint only one-tenth the size of the incoming wavelength, the PPAC achieves benchmark performance in intensity-, frequency-, and polarization-sensitive detection. Operating at room temperature across 0.22-4.24 THz, it delivers sub-diffraction detection resolution and high-speed operation. Furthermore, we demonstrate its application in free-space THz polarization-coded communication and stealth imaging for physical property analysis. The unique design of PPAC enables strong absorption with weak signal detection, within a structure just 10^-5 times the excitation wavelength in thickness, an accomplishment beyond current technologies. By simultaneously resolving intensity, frequency, and polarization, this detector can replace multiple single-function devices, providing a compact and efficient solution for next-generation ultrawideband communication and high-resolution radar systems.